rút gọn
2-\(\frac{2}{19}\)+\(\frac{2}{43}\)- \(\frac{2}{1943}\)
3 - \(\frac{3}{19}\)+ \(\frac{3}{43}\)-\(\frac{3}{1943}\)
Rút gọn: A= \(\frac{2-\frac{2}{19}+\frac{2}{43}-\frac{2}{1943}}{3-\frac{3}{19}+\frac{3}{43}-\frac{3}{1943}}\):\(\frac{4-\frac{4}{29}+\frac{4}{41}-\frac{4}{2941}}{5-\frac{5}{29}+\frac{5}{41}-\frac{5}{2941}}\)
\(A=\frac{2.\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}{3.\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}:\frac{4\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}{5.\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}=\frac{2}{3}:\frac{4}{5}=\frac{2}{3}.\frac{5}{4}=\frac{5}{6}\)
Xin lỗi nha, mình chỉ biết làm bài này nhõn bằng cách qui đồng nhưng số lớn lắm!
A = \(\frac{2-\frac{2}{19}}{3-\frac{3}{19}}+\frac{\frac{2}{43}-\frac{2}{1943}}{\frac{3}{43}-\frac{3}{1943}}:\frac{4-\frac{4}{29}+\frac{4}{41}-\frac{4}{2941}}{5-\frac{5}{29}+\frac{5}{41}-\frac{5}{2941}}\)
A =\(\frac{2\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}{3\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}:\frac{4\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}{5\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}\)
=\(\frac{2}{3}:\frac{4}{5}=\frac{2}{3}.\frac{5}{4}=\frac{10}{12}=\frac{5}{6}\)
\(\frac{2-\frac{2}{19}+\frac{2}{43}-\frac{2}{1943}}{3-\frac{3}{19}+\frac{3}{43}-\frac{3}{1954}}\)
Ta có:
\(A=\frac{2-\frac{2}{19}+\frac{2}{43}-\frac{2}{1943}}{3-\frac{3}{19}+\frac{3}{43}-\frac{3}{1943}}\)
\(A=\frac{2\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}{3\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1943}\right)}\)
\(A=\frac{2}{3}\)
\(1-\frac{\frac{2}{19}+\frac{2}{43}-\frac{2}{2013}}{\frac{3}{19}+\frac{3}{43}-\frac{3}{2013}}\)
\(1-\frac{\frac{2}{19}+\frac{2}{43}-\frac{2}{2013}}{\frac{3}{19}+\frac{3}{43}-\frac{3}{2013}}\)= \(1-\frac{2\left(\frac{1}{19}+\frac{1}{43}-\frac{1}{2013}\right)}{3\left(\frac{1}{19}+\frac{1}{43}-\frac{1}{2013}\right)}\)= 1 - \(\frac{2}{3}\)=\(\frac{1}{3}\)
\(1-\frac{\frac{2}{19}+\frac{2}{43}-\frac{2}{2013}}{\frac{3}{19}+\frac{3}{43}-\frac{3}{2013}}=1-\frac{2\left(\frac{1}{19}+\frac{1}{43}-\frac{1}{2013}\right)}{3\left(\frac{1}{19}+\frac{1}{43}-\frac{1}{2013}\right)}\)=\(1-\frac{2}{3}=\frac{1}{3}\)
tính :
A=\(\frac{2-\frac{2}{19}+\frac{2}{43}-\frac{2}{1995}}{3-\frac{3}{19}+\frac{3}{43}-\frac{3}{1995}}:\frac{4-\frac{4}{29}+\frac{4}{41}-\frac{4}{2941}}{5-\frac{5}{29}+\frac{5}{41}-\frac{5}{2941}}\)
ai giải giùm mình nhé
ai rõ ra , mai mình cần nộp bài rùi
ai nhanh nhất và chính xác nhất mình sẽ k
\(A=\frac{2-\frac{2}{19}+\frac{2}{43}-\frac{2}{1995}}{3-\frac{3}{19}+\frac{3}{43}-\frac{3}{1995}}:\frac{4-\frac{4}{29}+\frac{4}{41}-\frac{4}{2941}}{5-\frac{5}{29}+\frac{5}{41}-\frac{5}{2941}}\)
\(\Rightarrow A=\frac{2\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1995}\right)}{3\left(1-\frac{1}{19}+\frac{1}{43}-\frac{1}{1995}\right)}:\frac{4\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}{5\left(1-\frac{1}{29}+\frac{1}{41}-\frac{1}{2941}\right)}\)
\(\Rightarrow A=\frac{2}{3}:\frac{4}{5}\)
\(\Rightarrow A=\frac{2}{3}.\frac{5}{4}\)
\(\Rightarrow A=\frac{10}{12}=\frac{5}{6}\)
\(\frac{2}{7}.5\frac{1}{4}-\frac{2}{7}.3\frac{1}{4}\)
\(11\frac{3}{13}\)\(11\frac{3}{13}-\left(2\frac{4}{7}+5\frac{3}{13}\right)\)
\(3\frac{14}{19}+\frac{13}{17}+\frac{35}{43}+6\frac{5}{19}+\frac{8}{43}\)
\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+1\frac{5}{7}\)
Tính bằng cách thuận tiện
1,\(\frac{13}{19}\left(\frac{19}{26}-\frac{71}{43}\right)+\frac{71}{43}\left(\frac{13}{19}-\frac{86}{71}\right)\)
2,\(\frac{5}{7}\left(\frac{1}{2}-\frac{1}{3}+\frac{4}{7}\right)+\left(\frac{1}{2}-\frac{1}{3}-\frac{4}{7}\right):\frac{7}{5}\)
\(A=\dfrac{5-\dfrac{5}{29}+\dfrac{5}{41}-\dfrac{5}{2941}}{3-\dfrac{3}{19}+\dfrac{3}{43}-\dfrac{3}{1943}}:\dfrac{4-\dfrac{4}{29}+\dfrac{4}{41}-\dfrac{4}{2941}}{2-\dfrac{2}{19}+\dfrac{2}{43}-\dfrac{2}{1943}}\)
Rút gọn
\(A=\dfrac{5-\dfrac{5}{29}+\dfrac{5}{41}-\dfrac{5}{2941}}{3-\dfrac{3}{19}+\dfrac{3}{43}-\dfrac{3}{1943}}:\dfrac{4-\dfrac{4}{29}+\dfrac{4}{41}-\dfrac{4}{2941}}{2-\dfrac{2}{19}+\dfrac{2}{43}-\dfrac{2}{1943}}\)
\(=\dfrac{5-\dfrac{5}{29}+\dfrac{5}{41}-\dfrac{5}{2941}}{3-\dfrac{3}{19}+\dfrac{3}{43}-\dfrac{3}{1943}}.\dfrac{2-\dfrac{2}{19}+\dfrac{2}{43}-\dfrac{2}{1943}}{4-\dfrac{4}{29}+\dfrac{4}{41}-\dfrac{4}{2941}}\)
\(=\dfrac{5\left(1-\dfrac{1}{29}+\dfrac{1}{41}-\dfrac{1}{2941}\right)}{3\left(1-\dfrac{1}{19}+\dfrac{1}{43}-\dfrac{1}{1943}\right)}.\dfrac{2\left(1-\dfrac{1}{19}+\dfrac{1}{43}-\dfrac{1}{1943}\right)}{4\left(1-\dfrac{1}{29}+\dfrac{1}{41}-\dfrac{1}{2941}\right)}\)
\(=\dfrac{5}{3}.\dfrac{2}{4}=\dfrac{10}{12}=\dfrac{5}{6}\)
Vì đề bài không yêu cầu tính nên bn có thể không tính ra như mk cux đc!
Rút gọn:
A=\(\frac{2-\frac{2}{19}+\frac{2}{23}-\frac{1}{1010}}{3-\frac{3}{19}+\frac{3}{23}-\frac{3}{2020}}\)\(.\frac{4-\frac{4}{29}+\frac{4}{41}-\frac{1}{505}}{5-\frac{5}{29}+\frac{5}{41}-\frac{1}{404}}\)
HD: Vũ Phương Vy em chỉ cần đặt ts c rồi rút gọn
ko chép lại đề nha
=\(A=\frac{2\left(1-\frac{2}{19}+\frac{2}{23}\right)-\frac{1}{1010}}{3\left(1-\frac{1}{19}+\frac{1}{23}-\frac{1}{2020}\right)}\)\(.\frac{4\left(1-\frac{1}{29}+\frac{1}{41}\right)-\frac{1}{505}}{5\left(1-\frac{1}{29}+\frac{1}{41}\right)-\frac{1}{404}}\)
rồi em chỉ cần rút gọn tiếp
p/s đến đây thấy đề kì kì sao đó
em chek lại đề đc k
đề đúng mà ko sai đâu nếu bạn ko tin thì xem bài 5 của đề này nhé : https://online-learning-izteach-aws-source-bucket.s3-ap-southeast-1.amazonaws.com/resource/49714800-4b02-11ea-a775-01bd84d6799a/4baf4091-c5ae-4d0f-819c-e9ee9eedd6a8/de-so-13-on-tap-va-cung-co-toan-6-pdf